Nutrient input from nitrogen deposition in the North China Plain

Transcription

1 Presentation in 16 th IPNC 29 Nutrient input from nitrogen deposition in the North China Plain Liu XJ 1, He CE 1, Kopsch J 2, Fangmeier A 2, Zhang FS 1 1 College of Resources & Environmental Sciences, CAU 2 Institute for Landscape & Plant Ecology, UHOH

2 Outline Background N deposition and its nutrient contribution to agroecosystems in the North China Plain Conclusion and outlook

3 Background information on China s economic growth and its pollution cost China s annual GDP growth rate ( ): ~1%; China s annual economy loss by environmental pollution ( ): 8-13% of total GDP or the total GDP growth in the past 3 years; China s annual economic loss by air pollution ( ): 2-3% of total GDP; Premature deaths from air pollution: 75, people per year in China. (Sources from: China Statistical Year Book ; Wang Qingyu 26; (Sources from: China Statistical Year Book, ; Wang Qingyu, 26; FAO, 27; Wen Jiabao, 28,)

4 Regional distribution of air pollution hotspots in the world Note:the pollution index values reflect the extent of air pollution.

5 Why do we focus on N deposition? Nitrogen acts as both nutrient and pollutant in ecosystems; Anthropogenic induced reactive N emissions increase continuously in China; The amount and distribution of nitrogen deposition are not very clear so far in China.

6 25 NH 3 emissions from China NH 3 emissions (Tg N yr -1 ) y =.43x R 2 = NO 2 emissions from China 2 NO 2 emissi ions -1 ) (Tg N yr y =.56x R 2 = T d i NH dno i i f Chi Trends in NH 3 and NO 2 emissions from China (Liu et al.,unpublished; Ayers and Yeung, Atmos. Environ. 3: )

7 SCIAMACHY troposheric NO 2 vertical columns averaged between December 23 and November 24 for East Asia. (Richater et al., Nature, 437(25): )

8 Questions concerned What are the scale and magnitude of atmospheric N deposition o in the North China Plain? Should we consider the nutrient contribution of airborne N input to agricultural systems in the North China Plain?

9 Outline Background N deposition and its nutrient contribution to agroecosystems in the North China Plain Conclusion and outlook

10 Monitoring Network Sites in China for N deposition in China North China Plain (~2 sites) 8

11 A case study on N deposition in North China Plain Quantifying Biomonitoring Dry deposition (aerosols s and gases) Wet deposition (rain and snowfall) ) Total deposition by indicator crops bioindication (passive monitoring) Molinia caerulea High volume sampler Wet-only sampler Self-made, based Poa annua Passive sampler Rain gauge on 15 N dilution Bromus hordeaceus Echinochloa crus-galli reduced N rye grass oxidised N total N nutrient ti tratios to compare with modelled deposition N-content (Kopsch et al., 25)

12 N wet deposition Concentration n (mg/l) NH4-N NO3-N DON Mean: 7.7 mg N/L BD DBW QZ NCP China WQ Beijing HM QD CP CAU N ha -1 yr -1 ) Wet deposition (kg CAU DBW CP QZ WQ BD HM QD NH4-N NO3-N DON Mean: 35 kg N/ha CAU DBW CP QZ WQ BD HM QD 1) Spatial and temporal variations of N wet deposition were found in the NCP; 2) Mean concentration and input of inorganic+organic N in rain were 7.7 mg N L -1 and 35 kg N ha -1 yr -1 at 8 sites of NCP, respectively; 3) Organic N contributed 23% of total N wet deposition, compared with that of NH 4 -N (48%) and NO 3 -N (29%). (Adapted from Zhang et al., 28 a,b)

13 Further study indicated that urea is an important component of organic N in rainwater % on average Dalian(28): 平均占总氮 9.2% N concentratio ion (umol/l) Urea NO3-N NH4-N N con ncentration (u umol/l) % on average CAU(28): 平均占总氮 9. 6% Urea NO3-N NH4-N No. of rainfall events (Bai ZC, unpublished data)

14 Before sand storm N dry deposition After sand storm Sand storm in Beijing (17 April 26) ~6 t N input onto the Biji Beijing area

15 Monitoring sites for N dry deposition in the North China Plain

16 g m -3 Concentra ation of PM 1 /μ Dynamics of the PM 1 concentration at DBW, Beijing during May to August 25 Average: 188 μg/m 3 Chinese threshold concentration EU threshold concentration 29-May 5-Jun 12-Jun 19-Jun 26-Jun 3-Jul 1-Jul 17-Jul 24-Jul 31-Jul Hourly Measurem ent at Dongbeiw ang (1.8.6) concentration [µg m-³] Ratios of PM1 and PM2.5 to TSP were 83% and 72%. TSP PM1 PM :-8: 8:-11: 11:-14: 14:-17: 17:-2: 2:-23: 23:-2: 2:-5: tim e (Kopsch et al., unpublished)

17 pnh4 + co ncentration (u ug N m -3 ) a DBW QZ pno3 - co ncentration (u g N m -3 ) b DBW QZ Summer Autumn Winter Spring Mean Summer Autumn Winter Spring Mean Ammonium (a) and nitrate (b) in PM 1 at DBW and QZ in the North China Plain (average of 26-28) (Shen et al, 29. Env Pollut. 157: )

18 DBW QZ NO ation (ug N m -3 2 concentra ) NH concentration (ug N m -3 3 ) Month-Year (Shen et al, 29. Aug-6 Sep-6 Oct-o6 Nov-6 Dec-6 Jan-7 Feb-7 Mar-7 Apr-7 May-7 Jun-7 Jul-7 Aug-7 Sep-7 Oct-7 Nov-7 Dec-7 Jan-8 Feb-8 Mar-8 Apr-8 May-8 Jun-8 Jul-8 Aug-8 Sep-8 Dynamics of NH 3 (A) and NO 2 (B) concentrations at DBW and QZ in the North China Plain (26-8) Env Pollut.157: )

19 N dry deposition in the North China Plain (averaged from 26 to 28) Reactive N N concentration # V & d Annual N input species (µg N m -3 ) (cm s -1 ) (kg N ha -1 ) Particles pnh ± ± 4.1 ±.77 pno ± ±.3 Gases NH ± ±1.6 NO ± ±2.9 HNO 3 66±.66 ± ±1 4.2 ±1.33 Sum # Average concentrations of 7 sites in NCP during Jun 25 and Oct 28; Average concentrations of 7 sites in NCP during Jun 25 and Oct 28; & Dry deposition velocity, according to Zapletal (1998). Environ. Pollut. 12(S1),

20 Total airborne N input in NCP: Tg N yr -1 N de eposition (kg N ha -1 ) A Wet (direct) Dry (direct) Total (indirect) (3-35) (5-55) (8-9) 43% B Wet deposition (39%) 2% 8% 3% 9% DON 11% NO 3 -N NH 4 -N pnh + 4 Dry deposition (61%) 5% 19% NH 3 pno - 3 NO 2 HNO 3 Wt Wet and ddry deposition of reactive N species in the North China Plain (A. Annual N deposition; B. Composition of reactive N species)

21 DBW QZ June - Sep. 25 June - Sep. 27 Mean Oct. 25- May 26 Oct. 26- May 27 Mean June 25- May 26 Oct. 26- Sep. 27 Mean Plant available N from deposition (kg N ha -1 ) Maize season Wheat season Maize+Wheat Plant available N deposition (26-28) at two sites in the North China Plain using 15 N dilution method (He et al., Ecol. Appl., accepted)

22 Concentrations of NH 3, NO 2, SO 2, PM 1, ammonium N, nitrate t N and sulfate in PM 1 (pnh 4 -N, pno 3 -N, pso 4 -S) at DBW, Beijing in August from 25 to 28 g/m 3 ) Conce entration (u NH 3 NO 2 SO 2 PM 1 pnh + 4 pno - 3 pso 2-4 (Shen et al., in review, Atm Env.)

23 Tropospheric p NO x concentration over China in August 28 compared with that in August 25-7 (average) August 28 (Olympic period) (Adapted from TEMIS (29))

24 Concentrations of PM 1, ammonium N and nitrate N in PM 1 (pnh 4 -N and pno 3 -N) at DBW, Beijing during August and October 28 m -3 ) Concent tration (ug During Olympics (9-24 Aug) After Olympics (24 Sep-9 Oct) After Olympics (1-23 Oct) PM 1 pnh 4+ -N pno 3- -N (Shen et al., in review)

25 Outline Background N deposition and its nutrient contribution to agroecosystems in the North China Plain Conclusion and outlook

26 Conclusion 1. Serious pollution of atmospheric reactive N species was observed in the North China Plain (NCP); 2. Wt Wet and ddry deposition of finorganic i and organic N species were up to 9 kg N ha -1 yr -1, nearly 6% of which could be utilized directly by crops according to the 15 N dilution method; 3. Reactive N pollution and deposition could be reduced substantially if anthropogenic emission sources were controlled strictly.

27 Outlook 1. Further quantification and mapping of N wet and dry deposition in NCP and China using national monitoring network and deposition models; 2 Systematic evaluation of N deposition impact (across 2. Systematic evaluation of N deposition impact (across N deposition gradient) on biodiversity and soil processes in ecosystems of northwest China, which are more sensitive to N and climate change.

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29 Thank you and welcome to Beijing!